KR20160149220A - Silver particle coating composition - Google Patents

Abstract

An excellent conductivity is exhibited by firing at a low temperature and a short time, and preferably, the silver particle coating composition is excellent in adhesion between the silver coating and the substrate. Silver nanoparticles (N) coated with a protective agent containing an aliphatic hydrocarbon amine, silver microparticles (M), and a dispersion solvent. The present invention also relates to a silver particle coating composition comprising a binder resin. The present invention also relates to a silver particle coating composition comprising a curable monomer and a polymerization initiator. The dispersing solvent includes at least a glycol ester solvent. To a silver particle coating composition suitable for intaglio offset printing.

Description

TECHNICAL FIELD [0001] The present invention relates to a silver particle coating composition,

The present invention relates to a silver particle-containing coating composition. The silver particle coating composition of the present invention is suitable for intaglio offset printing applications. The present invention is also applied to a coating composition containing metal particles containing a metal other than silver.

Silver nanoparticles can be sintered at low temperatures. In the production of various electronic devices using this property, a silver coating composition containing silver nanoparticles is used in order to form an electrode or a conductive circuit pattern on a substrate. Silver nanoparticles are usually dispersed in an organic solvent. Silver nanoparticles have an average primary particle diameter of several nanometers to several tens of nanometers, and usually their surfaces are coated with an organic stabilizer (a protecting agent). When the substrate is a plastic film or sheet, it is necessary to sinter the silver nanoparticles at a low temperature (for example, 200 DEG C or less) below the heat resistant temperature of the plastic substrate.

Especially recently, as a flexible printed wiring board, not only heat-resistant polyimide already used but also various plastic substrates such as PET (polyethylene terephthalate) and polypropylene which have lower heat resistance than polyimide but are easy to process and are less expensive An attempt has been made to form fine metal wiring (for example, silver wiring). When a substrate made of a plastic having low heat resistance is used, it is necessary to further sinter the metal nano-particles (for example, silver nanoparticles) at a low temperature.

For example, Japanese Patent Application Laid-Open No. 2008-214695 discloses a process for producing a complex containing at least silver, oleylamine and oxalate ions by reacting oxalic acid with oleylamine, A method of producing silver ultra-fine particles including generating ultrafine particles is disclosed (claim 1). Further, in the above method, when the above-mentioned oxalic acid silver and the oleylamine are reacted with a saturated aliphatic amine having a total carbon number of 1 to 18 (claims 2 and 3), the complex can easily be produced, It has been disclosed that the time required can be shortened, and silver ultrafine particles protected with these amines can be produced with higher yield (paragraph [0011]).

Japanese Patent Application Laid-Open No. 2010-265543 discloses a silver compound which is decomposed by heating to produce metal silver, a middle chain alkylamine having a boiling point of 100 ° C to 250 ° C and a middle chain alkylamine having a boiling point of 100 ° C to 250 ° C A coating method comprising a first step of preparing a silver compound, a compound containing the alkylamine and the alkyl diamine, and a second step of heating and decomposing the complex compound, is disclosed in a method for producing ultrafine particles (claims 3, Paragraphs [0061], [0062]).

JP-A-2012-162767 discloses a method in which an amine mixed solution containing an alkylamine having 6 or more carbon atoms and an alkylamine having 5 or less carbon atoms and a metal compound containing a metal atom are mixed to form a mixture of the metal compound and the amine A first step of producing a complex compound, and a second step of producing metal fine particles by heating and decomposing the complex compound (claim 1). It is also disclosed that the coating can disperse the fine particles in an organic solvent such as an alcohol solvent such as butanol, a non-polar solvent such as octane, or a mixed solvent thereof (paragraph [0079]).

Japanese Patent Application Laid-Open No. 2013-142172 discloses a method for producing silver nanoparticles, which comprises reacting an aliphatic hydrocarbon monoamine (A) containing an aliphatic hydrocarbon group and an amino group and having a total carbon number of 6 or more in the aliphatic hydrocarbon group, (B) an aliphatic hydrocarbon monoamine (B) containing an aliphatic hydrocarbon group and two amino groups and having a total carbon number of the corresponding aliphatic hydrocarbon group of 8 or less, the aliphatic hydrocarbon diamine (C), preparing a complex compound containing the silver compound and the amine by mixing the silver compound and the amine mixture to heat the complex compound and thermally decomposing the silver complex to form silver nanoparticles A method of producing silver nanoparticles including a silver nanoparticle Pass 1). It is also disclosed that a silver coating composition called silver ink can be prepared by dispersing the obtained silver nanoparticles in a suspended state in an appropriate organic solvent (dispersion medium), and examples of the organic solvent include pentane, hexane, heptane, Aliphatic hydrocarbon solvents such as decane, undecane, dodecane, tridecane, and tetradecane; Aromatic hydrocarbon solvents such as toluene, xylene, mesitylene and the like; Alcohol solvents such as methanol, ethanol, propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n- 0085]).

Japanese Patent Laid-Open Publication No. 2013-142173 discloses a method for producing silver nanoparticles, which comprises reacting an aliphatic hydrocarbon monoamine (A) containing an aliphatic hydrocarbon group and one amino group and having a total carbon number of 6 or more of the aliphatic hydrocarbon group, And an aliphatic hydrocarbon monoamine (B) containing one amino group and having a total number of carbon atoms of the aliphatic hydrocarbon group of 5 or less in a specific ratio, and mixing the silver compound and the amine mixture to prepare a mixture A method for producing silver nanoparticles comprising producing a compound and a complex containing the amine, and heating and decomposing the complex to form silver nanoparticles (Claim 1). It is also disclosed that a silver coating composition called so-called silver ink can be prepared by dispersing the obtained silver nanoparticles in a suitable organic solvent (dispersion medium) in a suspended state in the same manner as in the above-mentioned Japanese Patent Laid-Open Publication No. 2013-142172 , The same organic solvent is disclosed (paragraph [0076]).

International Publication No. WO2014 / 024721 discloses a process for producing a mixture of an aliphatic amine containing at least a branched aliphatic hydrocarbon monoamine (D) containing a branched aliphatic hydrocarbon group and an amino group and having a branched aliphatic hydrocarbon group having 4 or more carbon atoms, A method for producing silver nanoparticles comprising the steps of forming a silver complex and a complex containing the amine, and heating and decomposing the complex to form silver nanoparticles (claim 1).

Japanese Patent Application Laid-Open No. 2010-55807 discloses a conductive paste for use in an intaglio offset printing method using a silicon blanket including a silicone rubber, which is composed of a binder resin, a conductive powder, and a mixed solvent of a high swelling solvent and a low swelling solvent (Claim 1). As the conductive powder, silver powder is exemplified (paragraph [0033]). It is disclosed that the electroconductive powder preferably has a 50% cumulative diameter D ₅₀ of the particle size distribution of 0.05 탆 or more and 10 탆 or less, particularly 0.1 탆 or more and 2 탆 or less. In addition, it is disclosed that conductive powder in scales (Paragraph [0034]). Japanese Patent Application Laid-Open No. 2010-55807 discloses no silver nanoparticles whose surface is coated with a protective agent containing an aliphatic hydrocarbon amine. There is also no disclosure concerning the conductive performance.

JP-A-2010-90211 discloses a conductive ink composition containing conductive particles and an organic vehicle including a resin composition and a solvent (claim 1). And the conductive particles are Ag particles (claim 10). The conductive ink composition is used to form an electrode by intaglio offset printing (paragraph [0001]). The conductive particles include spherical conductive particles having an average particle diameter of 0.05 μm to 3 μm and flaky conductive particles having an average flake diameter of 0.1 μm or more and less than 3 μm (paragraph [0014]). Japanese Patent Application Laid-Open No. 2010-90211 discloses no silver nanoparticles whose surface is coated with a protective agent containing an aliphatic hydrocarbon amine. In addition, the firing conditions in the examples are not described (paragraph [0027], etc.), and there is no disclosure concerning the conductive performance by low-temperature firing.

Japanese Patent Laid-Open Publication No. 2011-37999 discloses a resin composition comprising a conductive powder, a resin solid at 25 占 폚, a monomer component selected from an oxetane-based monomer, an epoxy-based monomer and a vinyl ether-based monomer, a polymerization initiator and a specific organic solvent (Claim 1), and a conductive powder having a spherical shape with an average particle diameter of 1 탆 or less and a powder having an average particle diameter of 1 탆 or more and 3 탆 or less A spherical shape is disclosed to combine powders (paragraph [0017]). However, when the conductive ink of the same publication is used and baked at a low temperature (120 DEG C), sufficient conductivity is not obtained (paragraph [0054], Table 2). Japanese Patent Laid-Open Publication No. 2011-37999 does not disclose silver nanoparticles whose surface is coated with a protective agent containing an aliphatic hydrocarbon amine.

Japanese Patent Laid-Open Publication No. 2012-38615 discloses a resin composition containing silver particles, a resin solid at 25 占 폚, and an organic cyclic ether compound (bifunctional oxetane compound) and having a viscosity at 25 占 폚 of 3 to 30 Pa 占 퐏 Silver particles having a median diameter (D50) of 0.2 to 0.9 占 퐉 are preferably used as silver particles with a median diameter (D50) of 1.0 to 10.0 占 퐉 for 100 parts by mass of silver particles Mass part is used in combination (claim 6, paragraph [0012]). However, when the paste is used and the low temperature baking (140 DEG C) is conducted for the conductivity of the publication, sufficient conductivity is not obtained (paragraph [0046], Table 1). Japanese Patent Laid-Open Publication No. 2012-38615 discloses no silver nanoparticles whose surface is coated with a protective agent containing an aliphatic hydrocarbon amine.

Japanese Patent Application Laid-Open No. 2008-214695 Japanese Patent Application Laid-Open No. 2010-265543 Japanese Patent Laid-Open No. 1262767 Japanese Patent Application Laid-Open No. 2013-142172 Japanese Patent Application Laid-Open No. 2013-142173 WO2014 / 024721 Japanese Patent Application Laid-Open No. 2010-55807 Japanese Patent Application Laid-Open No. 2010-90211 Japanese Patent Application Laid-Open No. 2011-37999 Japanese Patent Laid-Open Publication No. 2012-38615

Silver nanoparticles have an average primary particle diameter of several nanometers to several tens of nanometers, and are more likely to aggregate than particles of micrometer (mu m) size. The reduction reaction of the silver compound (the thermal decomposition reaction in the above Patent Documents 1 to 6) so that the surface of the obtained silver nanoparticles is covered with an organic stabilizer (a protecting agent such as an aliphatic amine or an aliphatic carboxylic acid) Lt; / RTI >

On the other hand, the silver nanoparticles become a silver coating composition (silver ink, silver paste) containing the particles in an organic solvent. In order to exhibit conductivity, the organic stabilizer covering the silver nanoparticles must be removed to sinter the silver particles at the time of firing after application onto the substrate. When the firing temperature is low, the organic stabilizer is difficult to remove. If the degree of sintering of the silver particles is not sufficient, a low resistance value can not be obtained. That is, the organic stabilizer present on the surface of the silver nanoparticles contributes to the stabilization of the silver nanoparticles, while preventing the sintering of the nanoparticles (in particular, sintering at low temperature baking).

When an aliphatic amine compound and / or an aliphatic carboxylic acid compound having a relatively long chain (for example, 8 or more carbon atoms) is used as an organic stabilizer, mutual gaps between silver nanoparticles are easily ensured, . On the other hand, long-chain aliphatic amine compounds and / or aliphatic carboxylic acid compounds are difficult to remove when the firing temperature is low.

Thus, there is a trade-off relationship between the stabilization of silver nanoparticles and the manifestation of a low resistance value at low temperature baking.

In the above Patent Documents 7 to 10, there is no disclosure about silver nanoparticles whose surface is coated with a protective agent containing an aliphatic hydrocarbon amine, and there is no disclosure concerning that sufficient conductivity is obtained by low-temperature firing.

Accordingly, an object of the present invention is to provide a silver particle paint composition which exhibits excellent conductivity (low resistance value) by firing at a low temperature and a short time.

Further, a silver coating film (silver-fired film) obtained by applying (or printing) and firing a silver particle coating composition onto a substrate to be printed is required to have excellent adhesion with the substrate.

Accordingly, an object of the present invention is to provide a silver particle paint composition which exhibits excellent conductivity (low resistance value) by firing at a low temperature and a short time, and is excellent in adhesion between a silver coating .

However, when the silver particle coating composition is used for intaglio offset printing, it is necessary to improve the transferability of the silver coating composition from the blanket to the substrate to be printed. In the intaglio offset printing, first, the silver coating composition is filled in the concave portion of the intaglio plate, the silver coating composition filled in the concave portion is transferred to a blanket (usually made of silicone rubber), and then the blanket is printed The silver coating composition is transferred onto the substrate. At this time, when the blanket sucks the solvent of the silver coating composition to some extent and swells, thereby reducing the adhesion between the silver coating composition and the surface of the blanket, the transferability from the blanket to the substrate is improved.

Accordingly, an object of the present invention is to provide a silver coating composition which exhibits excellent conductivity (low resistance value) by firing at a low temperature and in a short time, and is also suitable for intaglio offset printing.

The present inventors have accomplished the present invention by using silver nanoparticles prepared by the so-called thermal decomposition method and surface-coated with a protective agent containing an aliphatic hydrocarbon amine and silver microparticles. The present invention includes the following inventions.

(1) silver nanoparticles (N) coated with a protective agent containing an aliphatic hydrocarbon amine,

Comprises microparticles (M)

A silver particle coating composition comprising a dispersion solvent.

(2) The silver nanoparticles (N)

The aliphatic hydrocarbon amine includes an aliphatic hydrocarbon monoamine (A) containing an aliphatic hydrocarbon group and an amino group and having a total carbon number of 6 or more of the aliphatic hydrocarbon group,

(B) an aliphatic hydrocarbon monoamine (B) containing an aliphatic hydrocarbon group and an amino group and having a total carbon number of 5 or less in the aliphatic hydrocarbon group, and an aliphatic hydrocarbon monoamine having an aliphatic hydrocarbon group and two amino groups, wherein the aliphatic hydrocarbon group has a total carbon number of 8 or less , And at least one of hydrocarbon diamine (C).

(3) The aliphatic hydrocarbon monoamine (A) is selected from the group consisting of a straight chain alkyl monoamine having a straight chain alkyl group having 6 to 12 carbon atoms and a branched alkyl monoamine having a branched alkyl group having 6 to 16 carbon atoms (2). ≪ / RTI >

(4) The silver particle coating composition according to the above (2) or (3), wherein the aliphatic hydrocarbon monoamine (B) is an alkyl monoamine having 2 to 5 carbon atoms.

(5) The aliphatic hydrocarbon diamine (C) described in any one of (2) to (4) above, wherein one of the two amino groups is a primary amino group and the other is an alkylenediamine which is a tertiary amino group. Silver particle coating composition.

The silver particle coating composition according to any one of the above-mentioned items, wherein the aliphatic hydrocarbon amine comprises the aliphatic hydrocarbon monoamine (A) and the aliphatic hydrocarbon monoamine (B).

The silver particle coating composition according to any one of the above-mentioned items, wherein the aliphatic hydrocarbon amine comprises the aliphatic hydrocarbon monoamine (A) and the aliphatic hydrocarbon diamine (C).

The silver particle coating composition according to any one of the above-mentioned items, wherein the aliphatic hydrocarbon amine comprises the aliphatic hydrocarbon monoamine (A), the aliphatic hydrocarbon monoamine (B) and the aliphatic hydrocarbon diamine (C).

The silver particle coating composition according to any one of the above-mentioned items, wherein the protective agent further comprises an aliphatic carboxylic acid in addition to the aliphatic amine.

The silver particle coating composition according to any one of the above-mentioned items, wherein the protective agent does not contain an aliphatic carboxylic acid.

(6) The silver particle coating composition according to any one of (1) to (5) above, wherein the aliphatic hydrocarbon amine is used in an amount of 1 to 50 moles relative to 1 mole of silver atoms of the silver nanoparticles (N) .

The silver nanoparticles (N)

The aliphatic hydrocarbon amine and the silver compound as a protective agent are mixed to produce a complex compound containing the silver compound and the amine,

And heating the complex compound to thermally decompose it.

The silver compound is preferably oxalic acid. The oxalic acid molecule contains two silver atoms. When the silver compound is oxalic acid, the amount of the aliphatic hydrocarbon amine as a total of 2 to 100 moles relative to 1 mole of oxalic acid may be used.

(7) The silver particle coating composition according to any one of (1) to (6), further comprising a binder resin.

(8) The binder resin is selected from the group consisting of a polyvinyl butyral resin, a polyester resin, an acrylic resin, an ethylcellulose resin, a phenol resin, a polyimide resin, a melamine resin and a melamine- (7). ≪ / RTI >

(9) The silver particle coating composition according to any one of (1) to (8), further comprising a curable monomer and a polymerization initiator.

(10) The silver particle coating composition according to (9), wherein the curable monomer contains at least one selected from the group consisting of an oxetane compound and an epoxy compound.

(11) The silver particle coating composition according to any one of (1) to (10), wherein the dispersing solvent comprises at least a glycol ester solvent.

(12) The silver particle coating composition according to any one of (1) to (11), which is used for intaglio offset printing. The intaglio offset printing includes gravure offset printing and the like.

(13)

(1) to (12) is coated on the substrate, and a silver conductive layer

≪ / RTI >

The electronic device includes various wiring boards, modules, and the like.

An electronic device comprising the steps of applying a silver particle coating composition according to any one of the preceding claims to a substrate to form a silver particle containing coating layer and then firing the coating layer to form a silver conductive layer ≪ / RTI >

The firing is carried out at a temperature of 200 DEG C or lower, for example 150 DEG C or lower, preferably 120 DEG C or lower, for 2 hours or shorter, for example 1 hour or shorter, preferably 30 minutes or shorter, more preferably 15 minutes or shorter Lt; / RTI > More specifically, the reaction is carried out under the conditions of about 90 ° C to 120 ° C and 10 minutes to 15 minutes, for example, at 120 ° C for 15 minutes.

Metal nanoparticles whose surface is coated with a protective agent containing an aliphatic hydrocarbon amine,

Metal microparticles,

A metal particle paint composition comprising a dispersing solvent.

The substrate may be selected from a plastic substrate, a ceramic substrate, a glass substrate, and a metal substrate.

In the present invention, the silver particle coating composition comprises silver nanoparticles (N) coated with a protective agent containing an aliphatic hydrocarbon amine and silver microparticles (M). In the coating layer of the silver particle coating composition on the substrate, silver nanoparticles (N) are drawn into gaps between silver microparticles (M). This improves the contact efficiency between the silver nanoparticles (N) and silver microparticles (M), and improves the conductivity by firing.

Silver nanoparticles (N) whose surface is coated with a protective agent containing an aliphatic hydrocarbon amine are prepared by a so-called thermal decomposition method of silver complexes. In the present invention, an aliphatic hydrocarbon amine compound which functions as a complexing agent and / or a protective agent includes aliphatic hydrocarbon monoamine (A) having 6 or more carbon atoms, aliphatic hydrocarbon monoamine (B) having 5 or less carbon atoms, When at least one of aliphatic hydrocarbon diamines (C) of 8 or less is used, the surface of the silver nanoparticles formed is covered with the aliphatic amine compound.

Since the carbon chain length of the aliphatic hydrocarbon monoamine (B) and the aliphatic hydrocarbon diamine (C) is short, even in the case of firing at a low temperature of 200 DEG C or less, for example 150 DEG C or less, preferably 120 DEG C or less, It is likely to be removed from the silver particle surface in a short time of 2 hours or less, for example 1 hour or less, preferably 30 minutes or less. In addition, the amount of the aliphatic hydrocarbon monoamine (A) adhering to the surface of the silver particles is reduced by the presence of the monoamine (B) and / or the diamine (C). Therefore, even in the case of firing at the low temperature, in the short time, these aliphatic amine compounds are easily removed from the surface of the silver particles, and the sintering of the silver particles proceeds sufficiently.

As described above, according to the present invention, it is possible to provide a silver particle paint in which the contact efficiency between the silver nanoparticles (N) and silver microparticles (M) is good, and the excellent conductivity (low resistance value) A composition (silver particle containing ink, or silver particle containing paste) is provided.

When the silver particle coating composition further contains a binder resin, the adhesion between the silver coating (silver-fired film) obtained by applying (or printing) and firing on the substrate to be printed and the substrate is excellent.

When the silver particle coating composition further contains a curable monomer and a polymerization initiator, the adhesion between the silver coating (silver-fired film) and the substrate is further improved, and the flexibility of the silver coating (silver-fired film) is improved. The followability of the silver fluoride film to a flexible substrate such as a plastic substrate is improved.

As described above, according to the present invention, excellent conductivity (low resistance value) is exhibited by firing at low temperature and in a short time, and the adhesion between the silver coating (silver plating film) and the substrate, Is excellent in flexibility of the silver particle coating composition.

In the silver particle coating composition of the present invention, when the silver nanoparticles (N) and the silver microparticles (M) are dispersed in a dispersion solvent containing a glycol ester solvent, When used for intaglio offset printing, the transferability of the silver ink from the blanket to the substrate is improved. In the intaglio offset printing, first, the silver coating composition is filled in the concave portion of the intaglio plate, and the silver coating composition filled in the concave portion is transferred and repaired to a blanket (usually made of silicone rubber). Thereafter, The coating composition is transferred. At this time, it is considered that the blanket swells to some extent by sucking the solvent of the silver coating composition, whereby the adhesion between the silver coating composition and the surface of the blanket is reduced, and the transferability from the blanket to the substrate is improved.

Thus, according to the present invention, there is provided a silver coating composition which exhibits excellent conductivity (low resistance value) by firing at a low temperature and in a short time, and is suitable for offset plate printing.

The present invention is also applicable to metal particle paint compositions containing metals other than silver.

According to the present invention, a conductive film and a conductive wiring can be formed on various kinds of plastic substrates having low heat resistance such as PET and polypropylene, preferably by intaglio offset printing. The silver particle coating composition of the present invention is suitable for use in recent electronic devices.

The silver particle coating composition of the present invention comprises silver nanoparticles (N) coated with a protective agent containing an aliphatic hydrocarbon amine, silver microparticles (M), and a dispersion solvent. Further, the silver particle coating composition includes both of a so-called silver ink and a silver paste.

[Silver nanoparticles (N) coated with an aliphatic hydrocarbon amine protecting agent]

The silver nanoparticles (N) are produced by mixing an aliphatic hydrocarbon amine and a silver compound to produce a complex containing the silver compound and the amine,

And heating the complex compound to thermally decompose it. Thus, the method of producing silver nanoparticles (N) mainly includes a step of producing a complex compound and a step of thermal decomposition of a complex compound. The obtained silver nanoparticles (N) are subjected to a dispersion process for producing a coating composition.

In the present specification, the term " nanoparticle " means that the size of primary particles (average primary particle diameter) obtained by observation with a scanning electron microscope (SEM) is less than 1000 nm. In addition, the particle size is intended to be the size (i.e., the size of the silver itself) excluding the protective agent (stabilizer) present (coated) on the surface. In the present invention, the silver nanoparticles have an average primary particle diameter of, for example, 0.5 nm to 100 nm, preferably 0.5 nm to 80 nm, more preferably 1 nm to 70 nm, and further preferably 1 nm to 60 nm .

In the present invention, as the silver compound, a silver compound which is easily decomposed by heating to generate silver metal is used. Examples of such silver compounds include carboxylic acids such as formic acid silver, acetic acid silver, oxalic acid silver, malonic acid silver, benzoic acid silver and phthalic acid silver; Silver halides such as silver fluoride, silver chloride, silver bromide, and silver iodide; Sulfuric acid, silver nitrate, carbonic acid silver and the like can be used, but oxalic acid is preferably used from the viewpoint that it easily generates metal silver by decomposition and hardly generates impurities other than silver. Oxalic acid is advantageous in that the content of silver is high and the metal silver is obtained as it is by thermal decomposition without requiring a reducing agent, and impurities derived from the reducing agent are hard to remain.

In the case of producing metal nanoparticles containing metals other than silver, a metal compound which is easily decomposed by heating to generate a desired metal is used in place of the silver compound. Examples of such a metal compound include a salt of a metal corresponding to the silver compound, for example, a metal carboxylate; Metal halides; Metal salt compounds such as metal sulfates, metal nitrates and metal carbonates can be used. Of these, oxalic acid salts of metals are preferably used from the viewpoint that the metal is easily produced by decomposition and impurities other than metal are hardly generated. Examples of other metals include Al, Au, Pt, Pd, Cu, Co, Cr, In, and Ni.

Further, in order to obtain a composite with silver, the silver compound may be used in combination with any other metal compound than silver. Other metals include Al, Au, Pt, Pd, Cu, Co, Cr, In, and Ni. Ag-Cu, Au-Ag-Cu, Au-Ag-Pd and the like are exemplified. On the basis of the whole metal, silver accounts for at least 20% by weight, usually at least 50% by weight, for example at least 80% by weight.

In the present invention, in the step of producing the complex compound, the aliphatic hydrocarbon amine and the silver compound may be mixed in the absence of the solvent, but it is preferable to produce the silver compound and the complex containing the amine by mixing in the presence of an alcohol solvent having 3 or more carbon atoms Do.

As the alcohol solvent, an alcohol having 3 to 10 carbon atoms, preferably an alcohol having 4 to 6 carbon atoms, can be used. For example, n-propanol (boiling bp: 97 ° C), isopropanol (bp: 82 ° C), n-butanol (bp: 117 ° C), isobutanol ), n-pentanol (bp: 136 캜), n-hexanol (bp: 156 캜), n-octanol (bp: 194 캜), 2-octanol bp: 174 占 폚). Of these, n-butanol, isobutanol, sec-butanol, tert-butanol, isobutanol, isobutanol, tert-butanol, Butanol and hexanol are preferred. Particularly, n-butanol and n-hexanol are preferable.

For the sufficient agitation of the silver compound-alcohol slurry, the alcohol solvent may be used in an amount of, for example, 120 parts by weight or more, preferably 130 parts by weight or more, more preferably 150 parts by weight It is better to use more than one. The upper limit of the amount of the alcoholic solvent is not particularly limited and may be, for example, 1000 parts by weight or less, preferably 800 parts by weight or less, more preferably 500 parts by weight or less based on 100 parts by weight of the silver compound .

In the present invention, mixing of an aliphatic hydrocarbon amine and a silver compound in the presence of an alcohol solvent having 3 or more carbon atoms may take several forms.

For example, first, a solid silver compound and an alcohol solvent may be mixed to obtain a silver compound-alcohol slurry [slurry forming step], and then an aliphatic hydrocarbon amine may be added to the obtained silver compound-alcohol slurry. The slurry refers to a mixture in which a solid silver compound is dispersed in an alcohol solvent. A solid silver compound is added to a reaction vessel, and an alcohol solvent is added thereto to obtain a slurry.

Alternatively, an aliphatic hydrocarbon amine and an alcohol solvent may be added to a reaction vessel, and a silver compound-alcohol slurry may be added thereto.

Examples of aliphatic hydrocarbon amines which function as a complexing agent and / or a protecting agent in the present invention include aliphatic hydrocarbon monoamines (A) in which the total number of carbon atoms in the hydrocarbon group is 6 or more and include aliphatic hydrocarbon groups and one amino group (B) an aliphatic hydrocarbon monoamine (B) in which the total number of carbon atoms in the aliphatic hydrocarbon group is not more than 5, and an aliphatic hydrocarbon diamine (C) in which the aliphatic hydrocarbon group and the total number of carbon atoms in the aliphatic hydrocarbon group is 8 or less May be used. Each of these components is usually used as an amine mixed solution. However, mixing of the amine with the silver compound (or its alcohol slurry) is not necessarily performed using mixed amines. The above-mentioned amines may be added to the silver compound (or its alcohol slurry) sequentially.

As used herein, the term " aliphatic hydrocarbon monoamine " refers to a compound containing one to three monovalent aliphatic hydrocarbon groups and one amino group, although it is an established term. The term "hydrocarbon group" is a group containing only carbon and hydrogen. However, the aliphatic hydrocarbon monoamine (A) and the aliphatic hydrocarbon monoamine (B) may have a substituent group containing a hetero atom (an atom other than carbon and hydrogen) such as an oxygen atom or a nitrogen atom . This nitrogen atom does not constitute an amino group.

The term " aliphatic hydrocarbon diamine " refers to an aliphatic hydrocarbon group (alkylene group) substituted with a hydrogen atom of the amino group and, in some cases, two amino groups interposed between the aliphatic hydrocarbon group and the aliphatic hydrocarbon group, ≪ / RTI > The aliphatic hydrocarbon diamine (C) may have a substituent group containing a hetero atom (an atom other than carbon and hydrogen) such as an oxygen atom or a nitrogen atom, if necessary, in the hydrocarbon group thereof. This nitrogen atom does not constitute an amino group.

The aliphatic hydrocarbon monoamine (A) having a total carbon number of 6 or more has a high function as a protective agent (stabilizer) on the silver particle surface produced by its hydrocarbon chain.

The aliphatic hydrocarbon monoamine (A) includes primary amines, secondary amines, and tertiary amines. Examples of primary amines include hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecyl And saturated aliphatic hydrocarbon monoamines having a linear aliphatic hydrocarbon group having 6 to 18 carbon atoms (e.g., alkylmonoamines) such as amine and octadecylamine. As the saturated aliphatic hydrocarbon monoamine, in addition to the above-mentioned straight chain aliphatic monoamine, a saturated aliphatic hydrocarbon having a branched aliphatic hydrocarbon group having 6 to 16 carbon atoms, preferably 6 to 8 carbon atoms, such as isohexylamine, 2-ethylhexylamine and tert- And branched aliphatic hydrocarbon monoamines. Cyclohexylamine may also be mentioned. Further, an unsaturated aliphatic hydrocarbon monoamine such as oleylamine (i.e., alkenyl monoamine) can be mentioned.

Examples of secondary amines which are linear are N, N-dipropylamine, N, N-dibutylamine, N, N-dipentylamine, N, N-dihexylamine, N, N-dodecylamine, N, N-didodecylamine, N-methyl-N-propylamine, N, N-dodecylamine, N, Dialkyl monoamines such as N-ethyl-N-propylamine, N-propyl-N-butylamine and the like. Examples of tertiary amines include tributylamine, trihexylamine, and the like.

Also, examples of the branching agent include secondary amines such as N, N-dihexylamine and N, N-di (2-ethylhexyl) amine. Also, tertiary amines such as triisopentylamine and tri (2-ethylhexyl) amine can be given. In the case of N, N-di (2-ethylhexyl) amine, the carbon number of the 2-ethylhexyl group is 8, but the total number of carbons contained in the amine compound is 16. In the case of tri (2-ethylhexyl) amine, the total number of carbons contained in the amine compound is 24.

Of the above-mentioned monoamines (A), saturated aliphatic hydrocarbon monoamines having 6 or more carbon atoms are preferable in the case of the straight-chain type. When the number of carbon atoms is 6 or more, when the amino group is adsorbed on the surface of the silver particles, the gap with the other silver particles can be ensured, so that the action of preventing the aggregation of the silver particles is improved. Although the upper limit of the number of carbon atoms is not particularly specified, a saturated aliphatic monoamine having a carbon number of up to 18 is generally preferable in consideration of easiness of obtaining and ease of removal at the time of calcination. In particular, alkyl monoamines having 6 to 12 carbon atoms such as hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine and dodecylamine are preferably used. Of the above-mentioned straight-chain aliphatic hydrocarbon monoamines, only one type may be used, or two or more types may be used in combination.

In addition, when a branched aliphatic hydrocarbon monoamine compound is used, compared with the case where a straight chain aliphatic hydrocarbon monoamine compound having the same carbon number is used, the steric aliphatic hydrocarbon group has a smaller deposition amount on the silver particle surface than the silver particle surface A larger area of < / RTI > As a result, with a smaller deposition amount on the surface of the silver particles, a suitable stabilization of the silver nanoparticles is obtained. Since the amount of the protective agent (organic stabilizer) to be removed at the time of firing is small, even in the case of firing at a low temperature of 200 DEG C or less, the organic stabilizer can be efficiently removed and the sintering of the silver particles proceeds sufficiently.

Among branched aliphatic hydrocarbon monoamines, branched alkyl monoamine compounds having 5 to 6 carbon atoms in the main chain such as isohexylamine and 2-ethylhexylamine are preferred. When the number of carbon atoms in the main chain is 5 to 6, appropriate stabilization of silver nanoparticles tends to be obtained. From the viewpoint of the steric factor of the branched aliphatic group, it is effective to branch at the second carbon atom on the N atom side, such as 2-ethylhexylamine. As the branched aliphatic monoamine, only one type may be used, or two or more types may be used in combination.

In the present invention, as the aliphatic hydrocarbon monoamine (A), the linear aliphatic hydrocarbon monoamine and the branched aliphatic hydrocarbon monoamine may be used in combination in order to obtain respective advantages.

The aliphatic hydrocarbon monoamine (B) having a total carbon number of 5 or less has a shorter carbon chain length than the aliphatic monoamine (A) having a total carbon number of 6 or more. Therefore, the aliphatic hydrocarbon monoamine has a low function as a protecting agent (stabilizer) Compared with the amine (A), the silver compound has a high polarity, and the silver compound has a high coordination ability with respect to silver, which is believed to be effective in accelerating complex formation. In addition, since the carbon chain length is short, it can be removed from the silver particle surface at a low temperature of 120 DEG C or lower, for example, or at a low temperature of 100 DEG C or lower for 30 minutes or 20 minutes or less. It is effective for low-temperature firing of nanoparticles.

Examples of the aliphatic hydrocarbon monoamine (B) include ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert- And saturated aliphatic hydrocarbon monoamines having 2 to 5 carbon atoms (i.e., alkylmonoamines) such as pentylamine. Further, dialkyl monoamines such as N, N-dimethylamine and N, N-diethylamine can be mentioned.

Among these, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, pentylamine, isopentylamine, tert-pentylamine and the like are preferable, and butylamine is particularly preferable. Only one of the aliphatic hydrocarbon monoamines (B) may be used, or two or more types may be used in combination.

The aliphatic hydrocarbon diamine (C) having a total carbon number of 8 or less has a high coordination ability with respect to silver of the silver compound, and is effective for promoting complex formation. The aliphatic hydrocarbon diamine generally has a higher polarity than the aliphatic hydrocarbon monoamine, and the coordination ability of the silver compound with respect to silver is increased. In addition, the aliphatic hydrocarbon diamine (C) has an effect of accelerating thermal decomposition at a lower temperature and in a shorter time in a thermal decomposition process of a complex compound, so that silver nanoparticles can be produced more efficiently. In addition, since the protective coating of the silver particle containing the aliphatic diamine (C) has a high polarity, dispersion stability of silver particles in a dispersion medium containing a solvent having a high polarity is improved. In addition, the aliphatic diamine (C) has a short carbon chain length. Therefore, even at a low temperature calcination of, for example, 120 占 폚 or below or about 100 占 폚 or less, It is effective for the low temperature and short time firing of the obtained silver nanoparticles.

Examples of the aliphatic hydrocarbon diamine (C) include, but are not limited to, ethylenediamine, N, N-dimethylethylenediamine, N, N'-dimethylethylenediamine, N, N-diethylethylenediamine, 1,3-propanediamine, N, N'-dimethyl-1,3-propanediamine, N, N-dimethyl- 1,3-propanediamine, N, N-dimethyl-1,4-butanediamine, N, N'- 1,4-butanediamine, N, N'-dimethyl-1,4-butanediamine, N, Hexanediamine, N, N'-dimethyl-1,6-hexanediamine, 1,7-heptanediamine, , 1,8-octanediamine, and the like. All of these are alkylenediamines having 8 or less carbon atoms, at least one of the two amino groups being a primary amino group or a secondary amino group, and the silver compound has a high coordinating ability to silver and is effective for promoting complex formation.

Of these, N, N-dimethylethylenediamine, N, N-diethylethylenediamine, N, N-dimethyl- One of two amino groups such as dimethyl-1,4-butanediamine, N, N-diethyl-1,4-butanediamine and N, N-dimethyl- NH ₂ ), and the other one is a tertiary amino group (-NR ¹ R ² ). Preferred alkylenediamines are represented by the following structural formula.

R ¹ R ² NR-NH ₂

Herein, R represents a divalent alkylene group, R ¹ and R ² may be the same or different and represent an alkyl group, provided that the total number of carbon atoms of R, R ¹ and R ² is 8 or less. The alkylene group usually does not contain a hetero atom (an atom other than carbon and hydrogen) such as an oxygen atom or a nitrogen atom, but may have a substituent containing the hetero atom if necessary. The alkyl group does not usually contain a hetero atom such as an oxygen atom or a nitrogen atom, but may have a substituent containing the above hetero atom if necessary.

If one of the two amino groups is a primary amino group, the coordination ability of the silver compound with respect to silver becomes high, which is favorable for forming a complex. When the other one is a tertiary amino group, Therefore, it is prevented that the complex formed becomes complex network structure. When the complex has a complex network structure, a high temperature may be required for the thermal decomposition step of the complex. Of these, diamines having a total carbon number of 6 or less are preferable, and diamines having a total carbon number of 5 or less are more preferable from the viewpoint that even at low temperature baking, the silver can be removed from the silver particle surface in a short time. Only one kind of the aliphatic hydrocarbon diamine (C) may be used, or two or more kinds may be used in combination.

In the present invention, at least one of the aliphatic hydrocarbon monoamine (A) having 6 or more carbon atoms, the aliphatic hydrocarbon monoamine (B) having 5 or less carbon atoms and the aliphatic hydrocarbon diamine (C) having 8 or less carbon atoms (A) + (B) + (C)] is used as a reference, for example,

The amount of the aliphatic monoamine (A): 5 mol% to 65 mol%

The total amount of the aliphatic monoamine (B) and the aliphatic diamine (C) is 35 mol% to 95 mol%

. By setting the content of the aliphatic monoamine (A) to 5 to 65 mol%, the protective layer stabilizing function of the surface of silver particles produced by the carbon chain of the component (A) is easily obtained. If the content of the component (A) is less than 5 mol%, the protective stabilization function may be poorly expressed. On the other hand, when the content of the component (A) exceeds 65 mol%, the protective stabilizing function is sufficient, but the component (A) is hardly removed by low-temperature firing. When the branched aliphatic monoamine is used as the component (A), the amount of the aliphatic monoamine (A) is preferably 5 to 65 mol%

The branched aliphatic monoamine: 10 mol% to 50 mol%

.

When the aliphatic monoamine (A) and the aliphatic monoamine (B) and the aliphatic diamine (C) are both used, the ratio of the aliphatic monoamine (B) and the aliphatic diamine (C) is not particularly limited, B) + (C)], for example,

The amount of the aliphatic monoamine (A): 5 mol% to 65 mol%

The aliphatic monoamine (B) is used in an amount of 5 mol% to 70 mol%

The aliphatic diamine (C) is used in an amount of 5 mol% to 50 mol%

. When the branched aliphatic monoamine is used as the component (A), the amount of the aliphatic monoamine (A) is preferably 5 to 65 mol%

The branched aliphatic monoamine: 10 mol% to 50 mol%

.

In this case, the lower limit of the content of the component (A) is preferably 10 mol% or more, more preferably 20 mol% or more. The upper limit of the content of the component (A) is preferably 65 mol% or less, and more preferably 60 mol% or less.

By setting the content of the aliphatic monoamine (B) in the range of 5 mol% to 70 mol%, it is easy to obtain a promoting effect of complex formation and can contribute to low temperature and short time firing by itself, The action of helping to remove the diamine (C) from the surface of the silver particle is apt to be obtained. When the content of the component (B) is less than 5 mol%, the complex formation promoting effect is weak, or the component (C) is difficult to remove from the silver particle surface at the time of firing. On the other hand, when the content of the component (B) exceeds 70 mol%, the complex formation promoting effect is obtained, but the content of the aliphatic monoamine (A) relatively decreases, It is difficult to obtain. The lower limit of the content of the component (B) is preferably 10 mol% or more, and more preferably 15 mol% or more. The upper limit of the content of the component (B) is preferably 65 mol% or less, more preferably 60 mol% or less.

By setting the content of the aliphatic diamine (C) in the range of 5 to 50 mol%, the effect of accelerating complex formation and accelerating the thermal decomposition of the complex is easily obtained, and the protective coating of silver particles containing the aliphatic diamine (C) The dispersion stability of the silver particles in the dispersion medium containing a solvent having a high polarity is improved. If the content of the component (C) is less than 5 mol%, the complex formation promoting effect and the complex thermal decomposition promoting effect may be weak. On the other hand, when the content of the component (C) exceeds 50 mol%, the effect of accelerating complex formation and accelerating thermal decomposition of the complex is obtained, but the content of the aliphatic monoamine (A) It is difficult to obtain the protective stabilization of the particle surface. The lower limit of the content of the component (C) is preferably 5 mol% or more, and more preferably 10 mol% or more. The upper limit of the content of the component (C) is preferably 45 mol% or less, more preferably 40 mol% or less.

When the aliphatic monoamine (A) and the aliphatic monoamine (B) are used (the aliphatic diamine (C) is not used), the use ratio thereof is not particularly limited. However, , Based on the total amines [(A) + (B)], for example,

The amount of the aliphatic monoamine (A): 5 mol% to 65 mol%

35 to 95 mol% of the aliphatic monoamine (B)

. When the branched aliphatic monoamine is used as the component (A), the amount of the aliphatic monoamine (A) is preferably 5 to 65 mol%

The branched aliphatic monoamine: 10 mol% to 50 mol%

.

When the aliphatic monoamine (A) and the aliphatic diamine (C) are used (the aliphatic monoamine (B) is not used), the use ratio thereof is not particularly limited. However, , Based on the total amines [(A) + (C)], for example,

The amount of the aliphatic monoamine (A): 5 mol% to 65 mol%

35 to 95 mol% of the aliphatic diamine (C)

. When the branched aliphatic monoamine is used as the component (A), the amount of the aliphatic monoamine (A) is preferably 5 to 65 mol%

The branched aliphatic monoamine: 10 mol% to 50 mol%

.

The proportions of the aliphatic monoamine (A), the aliphatic monoamine (B) and / or the aliphatic diamine (C) are all examples and various modifications are possible.

In the present invention, when the aliphatic monoamine (B) and / or the aliphatic diamine (C) having a high coordinating ability to the silver of the silver compound are used, the aliphatic monoamine (A ) On the surface of the silver particles is less than the amount of the silver particles. Therefore, even in the case of firing at a low temperature for a short time, these aliphatic amine compounds are easily removed from the surface of the silver particles, and the sintering of the silver particles N proceeds sufficiently.

In the present invention, the total amount of the aliphatic hydrocarbon amine (for example, (A), (B) and / or (C)) is not particularly limited, To about 50 moles. When the total amount of the amine components [(A), (B) and / or (C)] is less than 1 mole relative to 1 mole of silver atoms, silver compounds which are not converted into complex compounds remain in the complex- In the subsequent thermal decomposition step, there is a possibility that the uniformity of the silver particles is impaired and the silver particles are enlarged or the silver compound is left without thermal decomposition. On the other hand, even if the total amount of the amine components [((A), (B) and / or (C)] exceeds about 50 moles per 1 mole of the silver atom, In order to prepare a dispersion of silver nanoparticles, the total amount of the amine components may be about 2 moles or more, for example. When the total amount of the amine components is about 2 to 50 moles, The lower limit of the total amount of the amine components is preferably 2 moles or more, and more preferably 6 moles or more, relative to 1 mole of silver atoms of the silver compound. 2 < / RTI >

In the present invention, an aliphatic carboxylic acid (D) may further be used as a stabilizer in order to further improve the dispersibility of the silver nanoparticles (N) in the dispersion medium. The aliphatic carboxylic acid (D) may be used together with the amines, or may be used in the amine mixture. By using the aliphatic carboxylic acid (D), the stability of the silver nanoparticles, in particular, the stability in the state of a paint dispersed in an organic solvent may be improved.

As the aliphatic carboxylic acid (D), a saturated or unsaturated aliphatic carboxylic acid is used. For example, there may be mentioned acid addition salts such as butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, pentadecanoic acid, hexadecanoic acid, , Saturated aliphatic monocarboxylic acids having 4 or more carbon atoms such as octadecanoic acid, nonadecanoic acid, icosanoic acid and eicosanoic acid; And unsaturated aliphatic monocarboxylic acids having 8 or more carbon atoms such as oleic acid, elaidic acid, linolic acid and palmitoleic acid.

Of these, saturated or unsaturated aliphatic monocarbons having 8 to 18 carbon atoms are preferred. When the number of carbon atoms is 8 or more, when the carboxylic acid group is adsorbed on the surface of the silver particles, the gap with the other silver particles can be ensured, so that the action of preventing aggregation of the silver particles is improved. A saturated or unsaturated aliphatic monocarboxylic acid compound having a carbon number of up to 18 is usually preferable in consideration of easiness of availability and ease of removal during firing. Particularly, octanoic acid, oleic acid and the like are preferably used. Of these aliphatic carboxylic acids (D), only one type may be used, or two or more types may be used in combination.

When used, the aliphatic carboxylic acid (D) may be used in an amount of, for example, about 0.05 to 10 mol, preferably 0.1 to 5 mol, per mol of the silver atom of the silver compound in the raw material, May be used in an amount of 0.5 to 2 mol. When the amount of the component (D) is less than 0.05 mol based on 1 mol of the silver atom, the stability improving effect in the dispersion state due to the addition of the component (D) is weak. On the other hand, when the amount of the component (D) exceeds 10 mols, the stability improving effect in the dispersed state is saturated and the removal of the component (D) at low temperature firing becomes difficult. However, considering the removal of the component (D) at low-temperature firing, the aliphatic carboxylic acid (D) may not be used.

In the present invention, usually, a mixed solution containing each aliphatic hydrocarbon amine component to be used; For example, a mixed solution of the aliphatic monoamine (A) and an amine containing at least one of the aliphatic monoamine (B) and the aliphatic diamine (C) is further prepared.

Amine mixture can be prepared by stirring the respective amine (A), (B) and / or (C) component and, if used, the carboxylic acid (D) component at a predetermined ratio at room temperature.

An aliphatic hydrocarbon amine mixed solution containing each amine component is added to the silver compound (or an alcohol slurry thereof) to produce a complex compound containing the silver compound and the amine [production process of complex compound]. Each of the amine components may be added to the silver compound (or its alcohol slurry) in this order instead of a mixed solution.

In the case of producing metal nanoparticles containing metals other than silver, a metal compound (or an alcohol slurry thereof) containing a target metal is used in place of the silver compound (or its alcohol slurry).

(Or an alcohol slurry thereof) or a metal compound (or an alcohol slurry thereof) and a predetermined amount of an amine mixed solution are mixed. Mixing may be carried out at room temperature. The " normal temperature " is intended to be 5 to 40 DEG C depending on the ambient temperature. For example, 5 to 35 占 폚 (JIS Z 8703), 10 to 35 占 폚, 20 to 30 占 폚. But may be a normal room temperature (for example, in the range of 15 to 30 占 폚). At this time, the stirring of the compound or the coordination reaction of amines on the silver compound (or the metal compound) accompanies the heat, so that even if the mixture is properly cooled and stirred with stirring so as to be within the above temperature range, for example, do. Is carried out in the presence of an alcohol having 3 or more carbon atoms, stirring and cooling can be preferably performed. The excess of alcohol and amines serves as the reaction medium.

In the thermal decomposition method of amine complexes, conventionally, a liquid aliphatic amine component was first charged into a reaction vessel, and a silver compound (silver oxalate) was charged into the reaction vessel. The aliphatic amine component of the liquid is a flammable substance, so there is a risk of the introduction of the silver compound into the powder. That is, there is a risk of ignition by static electricity due to the input of silver compound of powder. Further, by the addition of the silver compound of the powder, there is a risk that the adduct formation reaction proceeds locally and the exothermic reaction explodes. This risk can be avoided when mixing with a mixture of a compound and an amine is carried out in the presence of the alcohol. Therefore, it is also safe in industrial manufacture that is scaled up.

Since the resulting complex generally exhibits a color corresponding to its constituent components, the end point of the complex reaction can be detected by detecting the end of the color change of the reaction mixture by an appropriate spectroscopic method or the like. Further, although the complex compound formed by oxalic acid is generally colorless (observed as white in the naked eye), the generation state of the complex compound can be detected based on the morphological change such as the viscosity change of the reaction mixture . For example, the reaction time for the formation of the complex is about 30 minutes to 3 hours. In this way, silver-amine complexes (or metal-amine complexes) are obtained in a medium composed mainly of alcohols and amines.

Then, the obtained complex is heated and thermally decomposed to form silver nanoparticles (N) (thermal decomposition process of complex compound). When metal compounds other than silver are used, desired metal nanoparticles are formed. Silver nanoparticles (metal nanoparticles) are formed without using a reducing agent. However, if necessary, a suitable reducing agent may be used as long as the effect of the present invention is not impaired.

In such a metal amine complex decomposition method, amines generally form a film on the surface of the formed metal fine particles while controlling the manner in which the atomic metal generated by the decomposition of the metal compound coagulates to form fine particles. Thereby preventing re-aggregation between the fine particles. That is, by heating a complex of a metal compound and an amine, the metal compound is thermally decomposed while maintaining the coordination bond of the amine to the metal atom to form an atomic metal, and then the metal atoms for the amine are coagulated to form an amine protective film It is believed that coated metal nanoparticles are formed.

The thermal decomposition at this time is preferably carried out while stirring the complex in a reaction medium composed mainly of alcohol (if used) and amines. The thermal decomposition may be carried out within a temperature range in which the coating is formed of nanoparticles (or coated metal nanoparticles), but from the viewpoint of preventing the desorption of the amine from the silver particle surface (or the surface of the metal particle) It is preferable to perform at a low temperature. In the case of a complex of oxalic acid, for example, it may be about 80 to 120 ° C, preferably about 95 to 115 ° C, more specifically about 100 to 110 ° C. In the case of complexes of silver oxalate, decomposition occurs by heating at about 100 ° C or so, and silver ions are reduced, so that silver nanoparticles can be obtained. Although the thermal decomposition of oxalic acid itself generally occurs at about 200 ° C, the reason why the thermal decomposition temperature is lowered to about 100 ° C by forming silver-amine complex oxalic acid is not clear. However, It is presumed that when the complex is formed, the coordination polymer structure formed by the pure oxalic acid is cut off.

The thermal decomposition of the complex is preferably carried out in an inert gas atmosphere such as argon, but thermal decomposition can also be performed in the air.

By thermal decomposition of the complex compound, it becomes a suspension showing blue luster. Removal of excess amine from the suspension, for example, precipitation of silver nanoparticles (or metal nanoparticles), and decantation / cleaning with an appropriate solvent (water or organic solvent) are carried out, The stable coating provides nanoparticles (N) (or coated metal nanoparticles) (post-treatment of silver nanoparticles). After the washing operation and drying, a powder of a nanoparticle (or coated metal nanoparticle) of a desired stable coating is obtained. However, the silver nanoparticles (N) in the wet state may be provided for the production of the silver nanoparticle-containing ink.

Water or organic solvents are used for decanting and cleaning operations. Examples of the organic solvent include aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane and tetradecane; Alicyclic hydrocarbon solvents such as cyclohexane; Aromatic hydrocarbon solvents such as toluene, xylene, mesitylene and the like; Alcohol solvents such as methanol, ethanol, propanol, butanol and the like; Acetonitrile; And a mixed solvent thereof may be used.

Considering the intaglio offset printing application, a glycol solvent may be used as the organic solvent for the decantation / cleaning operation. Examples of the glycol solvent include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether , Dipropylene glycol monomethyl ether, and other glycol monoethers. As the glycol-based solvent, only one type may be used, or two or more types may be used in combination.

In the process for forming silver nanoparticles of the present invention, since there is no need to use a reducing agent, there is no by-product derived from the reducing agent, and the separation of the coated silver nanoparticles from the reaction system is also simple. Loses. However, if necessary, a suitable reducing agent may be used as long as the effect of the present invention is not impaired.

In this way, silver nanoparticles (N) coated with a protective agent are formed. The protective agent includes, for example, the aliphatic monoamine (A), and further contains either or both of the aliphatic monoamine (B) and the aliphatic diamine (C) (D). The content ratio thereof in the protective agent is equivalent to the use ratio thereof in the amine mixed solution. The same is true for metal nanoparticles.

[Silver microparticles (M)]

In the present specification, the term "microparticle" means that the average particle diameter is 1 μm or more and 10 μm or less. Silver microparticles (M) are different from the silver nanoparticles (N) and do not have an aliphatic hydrocarbon amine protecting agent on the surface thereof. In the present invention, the silver microparticles may be spherical particles, but may be flake-shaped particles. The flaky particles are intended to have an aspect ratio, that is, a ratio (diameter / thickness) of the diameter to the thickness of the microparticles of, for example, 2 or more. The flaky particles tend to have a larger contact area with respect to the spherical particles than the spherical particles, thereby improving conductivity. The average particle diameter of the silver microparticles (M) is 50% cumulative diameter D50 of the particle size distribution, for example, 1 탆 to 5 탆, preferably 1 탆 to 3 탆. When the coating composition is used for gravure offset printing, the particle size is preferably small in view of fine line drawing (for example, L / S = 30/30 占 퐉). (Shape: flake shape, D50: 2.78 mu m), AgS-050 (shape: spherical shape, D50: 1.4 mu m) of Silvette series of Dokuzaku Kagaku Co., C-34 (shape: spherical shape, D50: 0.6 占 퐉). The particle diameter is calculated by laser diffraction method.

[Mixing Ratio of Silver Nanoparticles (N) and Silver Microparticles (M)] [

In the present invention, the blending ratio of the silver nanoparticles (N) to the silver microparticles (M) is not particularly limited, but the ratio of silver nanoparticles (N) to silver microparticles (M) , E.g

Silver nanoparticles (N): 10 to 90 wt%

(M): 10 to 90 wt%

. By such a blending ratio, the effect of improving the conductivity by the low-temperature firing of the silver nanoparticles (N) and the effect of improving the stability of the silver coating composition by the silver microparticles (M) are easily obtained.

If the amount of the silver nanoparticles (N) is less than 10% by weight, the silver nanoparticles (N) entering into the gap between the silver microparticles (M) it's difficult. In addition, the effect of low-temperature firing of silver nanoparticles (N) coated with a protective agent containing an aliphatic hydrocarbon amine is also relatively small. For this reason, it is difficult to obtain an effect of improving conductivity by low-temperature firing. On the other hand, when the amount of the silver nanoparticles (N) exceeds 90% by weight, storage stability of the silver coating composition may be deteriorated. The silver nanoparticles (N) used in the present invention are covered with a protective agent containing an aliphatic hydrocarbon amine and have excellent low-temperature firing, but may be slowly sintered even when the coating composition is stored. Sintering causes viscosity increase of the coating composition. From this viewpoint, it is preferable to use at least 10% by weight of the silver microparticles (M) stable even at a room temperature.

Preferably,

Silver nanoparticles (N): 30 to 80 wt%

20 to 70% by weight of microparticles (M)

, And more preferably

Silver nanoparticles (N): 50 to 75 wt%

(M): 25 to 50 wt%

.

[Dispersing solvent]

The dispersion solvent may be any solvent capable of favorably dispersing silver nanoparticles (N) and silver microparticles (M). Examples of the organic solvent for obtaining the coating composition include aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane and tetradecane; Alicyclic hydrocarbon solvents such as cyclohexane and methylcyclohexane; Aromatic hydrocarbon solvents such as toluene, xylene, mesitylene and the like; Alcohol solvents such as methanol, ethanol, propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol and the like; Glycol solvents; Glycol ester solvents; And terpene solvents such as terpineol and dihydroterpineol. The desired type and amount of the organic solvent may be appropriately determined depending on the concentration or viscosity of the coating composition (silver ink, silver paste). The same is true for metal nanoparticles.

As the dispersion solvent, it is preferable to use a glycol-based solvent or a glycol ester-based solvent in consideration of intaglio offset printing applications. Examples of the glycol solvent include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, and the like, which are exemplified as organic solvents for decantation and cleaning of the silver nanoparticles (N) Glycol monoethers such as ethylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether (butyl carbitol: BC), propylene glycol monomethyl ether and dipropylene glycol monomethyl ether. As the glycol-based solvent, only one type may be used, or two or more types may be used in combination. The glycol solvent may be one derived from the one used in the decantation / cleaning operation of silver nanoparticles (N).

Examples of the glycol ester solvent include ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether Glycol monoester such as acetate (butyl carbitol acetate: BCA), propylene glycol monomethyl ether acetate (PMA; 1-methoxy-2-propyl acetate), dipropylene glycol monomethyl ether acetate). As the glycol ester-based solvent, only one type may be used, or two or more types may be used in combination.

The glycol solvent and the glycol ester solvent permeate the blanket made of silicone in intaglio offset printing. By permeating the solvent into the blanket, the blanket-ink interface is dried, the adhesion between the ink and the blanket is lowered, and the transfer property of the ink from the blanket to the substrate is improved. In addition, the glycol solvent and the glycol ester solvent also have a function of dissolving a binder resin, a curable monomer, and a polymerization initiator described later. Further, these solvents are preferable because they are low in volatility and hardly cause a change in the concentration of silver ink, and are also preferable from the viewpoint of working environment.

In the present invention, the total amount of the dispersing solvent is, for example, 30 wt% or more and 60 wt% or less, preferably 30 wt% or more and 50 wt% or less, more preferably 30 wt% or less, By weight or more and 40% by weight or less. From the viewpoint of intaglio offset printing use, if the amount of the dispersing solvent is less than 30% by weight, there is a possibility that the amount of the solvent is small and the transfer at the time of printing is not performed well. On the other hand, if the amount of the dispersing agent exceeds 60% by weight, there is a possibility that the solvent amount is large and fine line printing may not be performed well and low temperature baking may not be performed satisfactorily.

[Binder Resin]

In the present invention, it is preferable that the silver coating composition further comprises a binder resin. When the coating composition contains the binder resin, the adhesion between the silver-deposited film (conductive pattern) obtained by applying (or printing) and firing on the substrate to be printed and the substrate is improved and the flexibility of the silver- do.

Examples of the binder resin include a polyvinyl butyral resin, a polyester resin, an acrylic resin, an ethyl cellulose resin, a phenol resin, a polyimide resin, a melamine resin and a melamine-polyester resin . Among these, a polyvinyl butyral resin and a polyester-based resin are preferable, and it is also preferable to use both of them in combination.

The polyvinyl butyral resin is not particularly limited, but preferably has a weight average molecular weight (Mw) of about 10,000 to 100,000. Commercially available products of polyvinyl butyral resins include, for example, S-LEC B series manufactured by Sekisui Chemical Co., Ltd. Examples of the polyester-based resin include, but are not particularly limited to, polycaprolactone triol (commercially available as Flaxel 305 [PCL305] manufactured by Daicel Chemical Industries, Ltd.). Examples of commercially available products of ethylcellulose include ETHOCEL (registered trademark, Nissin Gasei) series.

The amount of the binder resin to be added is, for example, from 0.1 to 10% by weight, preferably from 2 to 5% by weight, based on the silver coating composition. With the added amount of the binder resin in this range, it is easy to improve the adhesion between the silver-oxidized film and the substrate and to improve the flexibility of the silver-oxidized film.

[Curable Monomer and Polymerization Initiator]

In the present invention, it is preferable that the silver coating composition further comprises a curing monomer and a polymerization initiator. When the silver particle coating composition contains the curable monomer and the polymerization initiator, the adhesion between the silver-containing film and the substrate is further improved, and the flexibility of the silver-containing film is improved. The followability to a flexible substrate such as a plastic substrate is improved.

Examples of the curable monomer include an oxetane compound and an epoxy compound. They have cationic polymerizability.

The oxetanyl compound may be a monofunctional oxetanyl compound having one oxetanyl group in the molecule, but a multifunctional oxetanyl compound having two or more oxetanyl groups in the molecule is preferable. For example, as the monofunctional oxetanyl compound, 3-ethyl-3-hydroxymethyloxetane (Alon oxetane series OXT-101 of Dojo detergent as a commercial product) and the like can be mentioned. As the bifunctional oxetanyl compound, there can be mentioned 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene, 3- -Ethyl- (3-oxetanyl)] methyl ether (OXT-221 as a commercial product of Dojo Kasei Co., Ltd.) and 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane. Further, polyfunctional oxetanyl compounds such as phenol novolak oxetane (PNOX as a commercial product, Doo Koti detergent) can be mentioned. Only one kind of oxetanyl compound may be used, but two or more kinds may be used.

The epoxy compound may be a monofunctional epoxy compound having one epoxy group in the molecule, but a polyfunctional epoxy compound having two or more epoxy groups in the molecule is preferable. Examples of the polyfunctional epoxy compound include bisphenol A diglycidyl ether, bisphenol A di-methylglycidyl ether, bisphenol F diglycidyl ether, bisphenol F di-methylglycidyl ether, Type epoxy resin, trisphenol methane triglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, Glycidyl ethers such as propylene glycol diglycidyl ether and polyethylene glycol diglycidyl ether; Diglycidyl esters such as phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester and dimeric acid diglycidyl ester; And the like. Only one type of polyfunctional epoxy compound may be used, but two or more types may be used.

The polymerization initiator may be one which initiates polymerization with heat or UV. However, from the necessity of sintering silver nanoparticles, it is preferable to initiate polymerization by heat. Examples of such cationic catalysts include aryldiazonium salts, aryliodonium salts, arylsulfonium salts, and allene-ion complexes. In the present invention, for example, trade names of "PP-33", "CP-66", "CP-77" (manufactured by ADEKA), "FC-509" (Sundead SI-80L), Suneide SI-100L, Suneide SI-110L (manufactured by GE Corporation), trade name "Suneide SI-60L" Commercially available products such as "CG-24-61" (manufactured by Shiba Japan Co., Ltd.) and the like can be used. In the present invention, a polymerization initiator (for example, SI-100L) which initiates a curing reaction at around 120 DEG C is preferable from the viewpoints of low temperature calcination (120 DEG C or lower), life of the catalyst and storage stability .

The addition amount of the curable monomer is, for example, 0.1% by weight or more and 10% by weight or less, preferably 2% by weight or more and 5% by weight or less based on the silver coating composition. With the addition amount of the curable monomer in this range, the adhesion between the silver-deposited film and the substrate is easily improved, and the flexibility of the silver-deposited film is easily improved. If the addition amount of the curable monomer is too large, contact between the silver particles is inhibited, and the conductivity tends to decrease. If the addition amount of the curable monomer is too small, improvement in flexibility of the silver oxide film is hardly obtained, and improvement in adhesion between the silver oxide film and the substrate tends to be hardly obtained. In curing, thermal curing is preferable, but radiation curing such as ultraviolet rays may be performed. The amount of the polymerization initiator to be added is, for example, from 0.1% by weight to 50% by weight, and preferably from 10% by weight to 35% by weight, based on the curable monomer. The addition amount capable of effecting the curable monomer may be appropriately selected.

In the present invention, the silver coating composition may further contain components other than those described above according to the purpose of the present invention.

The viscosity of the silver coating composition (silver ink) is in the range of, for example, 0.1 Pa · s or more and 30 Pa · s or less in the environmental temperature condition (for example, 25 ° C.) And preferably in the range of 5 Pa · s or more and 25 Pa · s or less. When the viscosity of the ink is less than 0.1 Pa · s, there is a possibility that the ink has too high fluidity, so that there is a problem in repairing the ink from the intaglio to the blanket and transferring the ink from the blanket to the substrate to be printed. On the other hand, when the viscosity of the ink exceeds 30 Pa · s, the fluidity of the ink is too low, so that the filling property of the intaglio plate to the concave portion may be deteriorated. When the filling property to the concave portion is deteriorated, the accuracy of the transferred pattern on the substrate is lowered, and problems such as disconnection of fine lines occur.

The coating of the dried or wet state obtained in the post-treatment process of the silver nanoparticles is carried out by using the powder of the nanoparticles (N), the powder of the silver microparticles (M), the dispersing solvent described above, By mixing and stirring the curable monomer and the polymerization initiator, an ink (or a paste) containing silver particles in a suspended state can be produced. The silver particles may vary depending on the purpose of use but may be, for example, 10% by weight or more, or 25% by weight or more, and preferably 20% by weight or more, for example, as a total of silver nanoparticles (N) and silver microparticles (M) 30% by weight or more. The upper limit of the content of the silver particles is desirably 80 wt% or less. When the coating is used with the nanoparticles (N) and the silver microparticles (M) and the dispersing solvent, the mixing and dispersion of the binder resin, the hardenable monomer and the polymerization initiator may be performed once or several times.

The silver coating composition (silver ink) obtained by the present invention is excellent in stability. The silver ink is stable, for example, at a silver concentration of 50% by weight for a period of one month or longer, without causing viscosity increase during storage at 5 ° C in a refrigerator.

The prepared silver coating composition (silver ink) is coated on the substrate by a known coating method, for example, intaglio offset printing, and then baked.

A patterned silver ink coating layer is obtained by intaglio offset printing, and a silver ink coating layer is fired to obtain a patterned silver conductive layer (silver fired film).

In intaglio offset printing, first, silver ink is filled in the concave portion of the intaglio, and silver ink charged in the concave portion is transferred to a blanket made of silicone rubber, and then silver ink is transferred from the blanket to the substrate . In the silver ink of the present invention, when a dispersing solvent containing a glycol ester solvent is used, the dispersing solvent infiltrates into the blanket to swell the blanket. Depending on the amount of solvent infiltrated into the blanket, the concentration of the silver ink retained on the blanket surface is increased, i.e., drying proceeds. As a result, the adhesion between the silver ink on the surface of the blanket and the blanket is reduced, and the transferability of the silver ink from the blanket to the substrate is improved.

If the ink further contains a binder resin, the adhesion between the silver-deposited film obtained by applying (or printing) and firing on the substrate to be printed is improved and the flexibility of the silver-deposited film is improved. When the ink further contains the curable monomer and the polymerization initiator, the adhesion between the silver-containing film and the substrate is further improved, and the flexibility of the silver-containing film is further improved. The followability to a flexible substrate such as a plastic substrate is improved.

The firing can be performed at a temperature of 200 占 폚 or less, for example, at room temperature (25 占 폚) or more and 150 占 폚 or less, preferably room temperature (25 占 폚) or more and 120 占 폚 or less. However, in order to complete sintering of silver by firing in a short time, it is preferable to perform the sintering at a temperature of 60 占 폚 to 200 占 폚, for example, 80 占 폚 to 150 占 폚, preferably 90 占 폚 to 120 占 폚. The firing time may be appropriately determined in consideration of the application amount of the silver ink, the firing temperature, and the like. For example, the firing time may be within a few hours (for example, 3 hours or 2 hours), preferably within 1 hour, More preferably 10 minutes to 20 minutes.

Since the silver nanoparticles are constituted as described above, the sintering of the silver particles proceeds sufficiently even by the firing step at a low temperature in a short time. As a result, excellent conductivity (low resistance value) is expressed. A silver conductive layer having a low resistance value (for example, 15 mu OMEGA cm or less, in a range of 5 to 15 mu OMEGA cm) is formed. The resistance value of the bulk silver is 1.6 mu OMEGA cm.

(PET) film, a polyethylene naphthalate (PEN) film and other polyester-based films, polypropylene, and the like can be used as the substrate, A general-purpose plastic substrate having a low heat resistance such as a polyolefin-based film can be suitably used. In addition, firing in a short time reduces the load on the general-purpose plastic substrate having low heat resistance and improves the production efficiency.

The silver conductive material obtained by the present invention can be used for various electronic devices such as an electromagnetic wave control material, a circuit board, an antenna, a heat sink, a liquid crystal display, an organic EL display, a field emission display (FED) An LED, an organic transistor, a capacitor, an electronic paper, a flexible battery, a flexible sensor, a membrane switch, a touch panel, an EMI shield, and the like. In particular, it is effective for an electronic material which requires surface smoothness, and is effective, for example, as a gate electrode of a thin film transistor (TFT) in a liquid crystal display.

The thickness of the conductive layer may be appropriately determined according to the intended use. Is not particularly limited and may be selected from the range of, for example, 5 nm to 10 탆, preferably 100 nm to 5 탆, and more preferably 300 nm to 2 탆.

Although the ink mainly containing silver nanoparticles has been described above, the present invention is also applied to an ink containing metal nanoparticles containing a metal other than silver.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[Resistivity value of silver reflow film]

The obtained silver-fired film was measured using a four-terminal method (Loresta GP MCP-T610). The measurement range limit of this device is 10 ⁷ Ωcm.

The following reagents were used in each Example and Comparative Example.

n-butylamine (MW: 73.14): manufactured by Tokyo Kasei Co., Ltd.

2-ethylhexylamine (MW: 129.25): reagent manufactured by Wako Pure Chemical Industries, Ltd.

n-octylamine (MW: 129.25) manufactured by Tokyo Kasei Co., Ltd.

Methanol: Wako Pure Chemical Industries Co., Ltd.

1-butanol: Wako Pure Chemical Industries Limited reagent grade

Oxalic acid (MW: 303.78): a product synthesized from silver nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) and oxalic acid dihydrate (manufactured by Wako Pure Chemical Industries, Ltd.)

[Example 1]

(Preparation of silver nanoparticles)

40.0 g (0.1317 mol) of oxalic acid was added to a 500 mL flask, and 60 g of n-butanol was added thereto to prepare an n-butanol slurry of silver oxalate. To this slurry was added dropwise an amine mixed solution of 115.58 g (1.5802 mol) of n-butylamine, 51.06 g (0.3950 mol) of 2-ethylhexylamine and 17.02 g (0.1317 mol) of n-octylamine at 30 ° C. After the dropwise addition, the mixture was stirred at 30 DEG C for 1 hour, and the complex formation reaction of the oxalic acid and the amine was proceeded. After the formation of the silver-amine complex of oxalic acid, the suspension was heated at 110 DEG C to thermally decompose the silver-amine complex oxalate to suspend the dark blue silver nanoparticles in the amine mixed solution.

The resulting suspension was cooled, and 120 g of methanol was added thereto and stirred. Thereafter, the silver nanoparticles were precipitated by centrifugation, and the supernatant was removed. The silver nanoparticles were then stirred with 120 g of diethylene glycol monobutyl ether (TOKYO KASEI), and then the silver nanoparticles were precipitated by centrifugation to remove the supernatant. Thus, silver nanoparticles in a wet state containing diethylene glycol monobutyl ether were obtained. As a result of the thermal balance using TI / DTA6300 manufactured by SII, the silver nanoparticles in the wet state occupied 90 wt% of the silver nanoparticles.

The silver nanoparticles in a wet state were observed using a scanning electron microscope (JSM-6700F manufactured by JEOL Ltd.) by a conventional method, and the average particle diameter of the silver nanoparticles was determined. As a result, the average particle diameter Primary particle diameter) was about 50 nm.

The average particle diameter was determined as follows. Silver nanoparticles were subjected to SEM observation, and the particle diameters of 10 silver particles arbitrarily selected in the SEM photograph were determined, and the average value thereof was taken as the average particle diameter.

(Production of silver ink)

1.2 g of di [1-ethyl- (3-oxetanyl)] methyl ether (OXT-221 available from Toagose KK) as a bifunctional oxetane monomer, 1.2 g of a polyvinyl butyral resin 0.3 g of polycaprolactone triol (PCL305, Daicel Chemical Industries, Ltd.), 0.3 g of a cationic polymerization initiator SI-100L (manufactured by San-shin Chemical Industry Co., Ltd.) and 0.1 g of diethylene glycol monobutyl ether acetate Manufactured by Daicel Chemical Industries, Ltd.) were mixed to completely dissolve the polyvinyl butyral resin.

6 g of the obtained solution was measured. 10 g of the silver nanoparticles in the wet state containing the diethylene glycol monobutyl ether were weighed. 6 g of the obtained solution, 10 g of the silver nanoparticles in the wet state, and 4 g of the flake shape were mixed with 4 g of microparticles (Silvestro series, product number TC-507A, manufactured by Toku Rikagaku Kagyusho Co., Ltd.) Ltd., Mazerstar KKK2508, manufactured by Kikai Co., Ltd.) for 30 seconds. Thereafter, stirring for 30 seconds in the kneader and stirring for 1 minute in the spatula were repeated twice. Thus, a blackish brown silver ink was produced.

The resulting silver ink was subjected to TG-DTA (simultaneous thermal analysis by differential thermal analysis) using TG / DTA6300 manufactured by SII, and the silver concentration in silver ink was determined to be 65 wt%. The viscosity of the silver ink was measured using a rheometer (rheometer MCR301, manufactured by Anton Paar), and it was found that 22 Pa · s (5 / s) and 12 Pa · s (10 / s) and 5 Pa · s (50 / s).

Table 1 shows the composition of the silver ink. In Table 1, the composition of each component is expressed in parts by weight based on 100 parts by weight as a whole. As described above, "from silver nanoparticles in wet state occupied 90 wt% of silver nanoparticles", "10 g of wet silver nanoparticles" = "silver nanoparticles 9 g itself" + "diethylene glycol mono 1 g of butyl ether ".

Therefore, in Table 1, "45 parts by weight of silver nanoparticles per se" and "5 parts by weight of diethylene glycol monobutyl ether" are shown.

(Printability of silver ink)

The silver ink was printed on a PEN film by a gravure offset printing apparatus having a blanket made of silicone (Minilabo Pine II, manufactured by Nihon Denshikimitsu Co., Ltd.), and the printability was evaluated. It was confirmed that a fine line of L / S = 30 mu m / 30 mu m could be transferred. Residues of the ink on the blanket were not visually observed.

(Adhesion to substrate)

The silver ink was coated on the ITO film and dried at 120 캜 for 30 minutes to form a coating film having a thickness of 5 탆. The resulting coating film was subjected to a cross-cut tape peeling test (25 pieces) using a cellophane adhesive tape (manufactured by Nichiban K.K.) in accordance with JIS K5600. And exhibited good adhesion.

Good: peeling 0/25

Poor: 1/25 or more for peeling

(Firing of silver ink)

The silver ink was applied onto a soda glass plate to form a coating film. After the formation of the coating film, the coating film was rapidly fired at 120 deg. C for 30 minutes in a blower drying furnace to form a 10 [micro] m thick sintered film. The resistivity of the obtained silver-fired film was measured by the four-terminal method, and it was 14.0 占 cm m and exhibited good conductivity. As described above, the silver ink exhibited excellent conductivity by firing at a low temperature and a short time.

[Example 2]

Silver nanoparticles were prepared in the same manner as in Example 1.

(Production of silver ink)

, 0.9 g of bifunctional oxetane monomer (OXT-221, manufactured by Toagose KK), 0.6 g of polyvinyl butyral resin (S-Rect B, product number BM-1, manufactured by Sekisui Chemical Co., , 0.3 g of a cationic polymerization initiator SI-100L (manufactured by San-shin Chemical Industry Co., Ltd.) and 6.9 g of diethylene glycol monobutyl ether acetate (Daicel Co., Ltd.) were mixed to prepare a polyvinyl butyral resin Lt; / RTI >

6 g of the obtained solution was measured. 10 g of the silver nanoparticles in the wet state containing the diethylene glycol monobutyl ether were weighed. 6 g of the obtained solution, 10 g of the silver nanoparticles in the wet state, and 4 g of the flake shape were mixed with 4 g of microparticles (Silvestro series, product number TC-507A, manufactured by Toku Rikagaku Kagyusho Co., Ltd.) Ltd., Mazer Star KKK2508), and the mixture was stirred and kneaded in the same manner as in Example 1 to prepare a blackish-brown silver ink.

The silver concentration in the ink was 65 wt%.

The viscosity of the ink was 22 Pa · s (5 / s), 11 Pa · s (10 / s) and 5 Pa · s (50 / s).

(Printability of silver ink)

The silver ink was printed on a PEN film by a gravure offset printing apparatus having a blanket made of silicone (Minilabo Pine II, manufactured by Nihon Denshikimitsu Co., Ltd.), and the printability was evaluated. It was confirmed that a fine line of L / S = 30 mu m / 30 mu m could be transferred. Residues of the ink on the blanket were not visually observed.

(Adhesion to substrate)

In the same manner as in Example 1, the silver ink was used to form a 5 탆 thick coating film on the ITO film. The obtained coating film was subjected to a cross-cut tape peeling test (25 pieces). And exhibited good adhesion.

(Firing of silver ink)

In the same manner as in Example 1, the silver ink was used to form a silver-plated film having a thickness of 10 mu m on a soda glass plate. The resistivity of the obtained silver-foil film was measured by a four-terminal method, and it was 12.0 占 cm m and exhibited good conductivity. As described above, the silver ink exhibited excellent conductivity by firing at a low temperature and a short time.

[Example 3]

Silver nanoparticles were prepared in the same manner as in Example 1.

(Production of silver ink)

, 0.9 g of bifunctional oxetane monomer (OXT-221, manufactured by Toagose KK), 0.6 g of polyvinyl butyral resin (S-Rect B, product number BM-1, manufactured by Sekisui Chemical Co., , 0.3 g of a cationic polymerization initiator SI-100L (manufactured by San-shin Chemical Industry Co., Ltd.) and 6.9 g of diethylene glycol monobutyl ether acetate (Daicel Co., Ltd.) were mixed to prepare a polyvinyl butyral resin Lt; / RTI >

6.2 g of the obtained solution was weighed. 8 g of the silver nanoparticles in the wet state containing the diethylene glycol monobutyl ether were weighed. The obtained solution (6.2 g), the wet silver nanoparticles (8 g) and the flake form were mixed with 5.8 g of microparticles (Silvestro series, product number TC-507A, manufactured by Toku Rikagaku Kagyusho Co., Ltd.) Ltd., Mazer Star KKK2508 manufactured by SEKI KABUSHIKI CO., LTD.) In the same manner as in Example 1 to prepare a blackish brown silver ink.

The silver concentration in the ink was 65 wt%.

The viscosity of the ink was 21 Pa · s (5 / s), 12 Pa · s (10 / s) and 5 Pa · s (50 / s).

(Printability of silver ink)

The silver ink was printed on a PEN film by a gravure offset printing apparatus having a blanket made of silicone (Minilabo Pine II, manufactured by Nihon Denshikimitsu Co., Ltd.), and the printability was evaluated. It was confirmed that a fine line of L / S = 30 mu m / 30 mu m could be transferred. Residues of the ink on the blanket were not visually observed.

(Adhesion to substrate)

In the same manner as in Example 1, the silver ink was used to form a 5 탆 thick coating film on the ITO film. The obtained coating film was subjected to a cross-cut tape peeling test (25 pieces). And exhibited good adhesion.

(Firing of silver ink)

In the same manner as in Example 1, the silver ink was used to form a silver-plated film having a thickness of 10 mu m on a soda glass plate. The resistivity of the obtained silver-foil film was measured by the four-terminal method, and it was 28.0 mu OMEGA .cm, which showed good conductivity. As described above, the silver ink exhibited excellent conductivity by firing at a low temperature and a short time.

[Comparative Example 1: No silver nanoparticles]

(Production of silver ink)

, 1.2 g of a bifunctional oxetane monomer (OXT-221, manufactured by Toagose Corporation), 0.9 g of a polyvinyl butyral resin (ESREC B, product number BM-1, manufactured by Sekisui Chemical Co., Ltd.) , 0.3 g of a cationic polymerization initiator SI-100L (manufactured by SANSHIN KAGAKU CO., LTD.), 1.5 g of diethylene glycol monobutyl ether (TOKYO KASEI Co., Ltd.) and 0.3 g of diethylene glycol monobutyl ether acetate Ltd.) were mixed to completely dissolve the polyvinyl butyral resin.

7 g of the obtained solution was measured. 7 g of the obtained solution and 13 g of microparticles (Silvestro series, product number TC-507A, made by Tokurikagakukyusho Co., Ltd.) were mixed with 7 g of the obtained solution in a rotary mixing kneader (Mazerstar KKK2508, manufactured by Kurashiki Kiso Kagaku Kabushiki Kaisha) And the mixture was stirred and kneaded in the same manner as in Example 1 to prepare a blackish brown silver ink.

The silver concentration in the ink was 65 wt%.

The viscosity of the ink was 21 Pa · s (5 / s), 12 Pa · s (10 / s) and 5 Pa · s (50 / s).

(Printability of silver ink)

The silver ink was printed on a PEN film by a gravure offset printing apparatus having a blanket made of silicone (Minilabo Pine II, manufactured by Nihon Denshikimitsu Co., Ltd.), and the printability was evaluated. It was confirmed that a fine line of L / S = 30 mu m / 30 mu m could be transferred. Residues of the ink on the blanket were not visually observed.

(Adhesion to substrate)

In the same manner as in Example 1, the silver ink was used to form a 5 탆 thick coating film on the ITO film. The obtained coating film was subjected to a cross-cut tape peeling test (25 pieces). And exhibited good adhesion.

(Firing of silver ink)

In the same manner as in Example 1, the silver ink was used to form a silver-plated film having a thickness of 10 mu m on a soda glass plate. When the resistivity of the obtained silver-fired film was measured by the four-terminal method, the conductivity was found to be 66.0 mu OMEGA cm. As described above, the silver ink was poor in conductivity due to the low-temperature and short-time firing.

[Comparative Example 2: No silver nanoparticles]

(Production of silver ink)

, 0.9 g of bifunctional oxetane monomer (OXT-221, manufactured by Toagose KK), 0.6 g of polyvinyl butyral resin (S-Rect B, product number BM-1, manufactured by Sekisui Chemical Co., Ltd.), 0.5 g of polycaprolactone triol , 0.3 g of a cationic polymerization initiator SI-100L (manufactured by SANSHIN KAGAKU CO., LTD.), 1.5 g of diethylene glycol monobutyl ether (TOKYO KASEI Co., Ltd.) and 0.3 g of diethylene glycol monobutyl ether acetate Ltd.) were mixed to completely dissolve the polyvinyl butyral resin.

7 g of the obtained solution was measured. 7 g of the obtained solution and 13 g of microparticles (Silvestro series, product number TC-507A, made by Tokurikagakukyusho Co., Ltd.) were mixed in a rotary-type kneader (Mazerstar KKK2508, manufactured by Kurashiki Kiso Kagaku Kabushiki Kaisha) In the same manner as in Example 1 to prepare a blackish brown silver ink.

The silver concentration in the ink was 65 wt%.

The viscosity of the ink was 20 Pa · s (5 / s), 11 Pa · s (10 / s) and 5 Pa · s (50 / s).

(Printability of silver ink)

The above silver ink was printed on a PEN film by a gravure offset printing apparatus having a blanket made of silicon (Minilabo Fine II, manufactured by Nihon Denshikimitsu Co., Ltd.) and evaluated for printing suitability, It was confirmed that a fine line of L / S = 30 mu m / 30 mu m could be transferred. Residues of the ink on the blanket were not visually observed.

(Adhesion to substrate)

In the same manner as in Example 1, the silver ink was used to form a 5 탆 thick coating film on the ITO film. The obtained coating film was subjected to a cross-cut tape peeling test (25 pieces). And exhibited good adhesion.

(Firing of silver ink)

In the same manner as in Example 1, the silver ink was used to form a silver-plated film having a thickness of 10 mu m on a soda glass plate. The resistivity of the resulting silver-deposited film was measured by the four-terminal method, and the conductivity was found to be 60.0 mu OMEGA cm. As described above, the silver ink was poor in conductivity by firing at a low temperature and a short time.

The results are shown in Table 1.

Claims (13)

Silver nanoparticles (N) coated with a protective agent containing an aliphatic hydrocarbon amine,
Comprises microparticles (M)
A silver particle coating composition comprising a dispersion solvent. 2. The silver nanoparticle (N) according to claim 1,
The aliphatic hydrocarbon amine includes an aliphatic hydrocarbon monoamine (A) containing an aliphatic hydrocarbon group and an amino group and having a total carbon number of 6 or more of the aliphatic hydrocarbon group,
(B) an aliphatic hydrocarbon monoamine (B) containing an aliphatic hydrocarbon group and an amino group and having a total carbon number of 5 or less in the aliphatic hydrocarbon group, and an aliphatic hydrocarbon monoamine having an aliphatic hydrocarbon group and two amino groups, wherein the aliphatic hydrocarbon group has a total carbon number of 8 or less And at least one of a hydrocarbon diamine (C). The method of claim 2, wherein the aliphatic hydrocarbon monoamine (A) is a linear alkyl monoamine having a straight chain alkyl group having 6 to 12 carbon atoms and a branched alkyl monoamine having a branched alkyl group having 6 to 16 carbon atoms Lt; RTI ID = 0.0 > 1, < / RTI > The silver particle coating composition according to claim 2 or 3, wherein the aliphatic hydrocarbon monoamine (B) is an alkyl monoamine having 2 to 5 carbon atoms. The aliphatic hydrocarbon diamine (C) according to any one of claims 2 to 4, wherein the aliphatic hydrocarbon diamine (C) is an alkylenediamine wherein one of the two amino groups is a primary amino group and the other is a tertiary amino group Coating composition. The silver particle coating composition according to any one of claims 1 to 5, wherein the aliphatic hydrocarbon amine is used in a total amount of 1 to 50 moles per mole of silver atoms of the silver nanoparticles (N). 7. The silver particle coating composition according to any one of claims 1 to 6, further comprising a binder resin. 8. The thermoplastic resin composition according to claim 7, wherein the binder resin is selected from the group consisting of a polyvinyl butyral resin, a polyester resin, an acrylic resin, an ethylcellulose resin, a phenol resin, a polyimide resin, a melamine resin and a melamine- Lt; RTI ID = 0.0 > 1, < / RTI > The silver particle coating composition according to any one of claims 1 to 8, further comprising a curable monomer and a polymerization initiator. The silver particle coating composition according to claim 9, wherein the curable monomer comprises at least one selected from the group consisting of an oxetane compound and an epoxy compound. 11. The silver particle coating composition according to any one of claims 1 to 10, wherein the dispersing solvent comprises at least a glycol ester-based solvent. 12. The silver particle coating composition according to any one of claims 1 to 11, which is used for intaglio offset printing. A substrate;
The silver particle coating composition according to any one of claims 1 to 12, which is applied on the substrate and fired,
≪ / RTI >